The Home Machinist!

When a completed engine that has been in service needs to be hydro tested, what is the procedure? Is the entire engine tested or are the relief valves, steam chests and cylinders, etc disconnected/removed and the holes plugged?

typically plug the relief valves and close the throttle.

not necessary to 'disconnect' anything except the pressure gauge if it will not safely display the hydro pressure.

I personally like to test the water glass also, because it SHOULD be able to take the hydro pressure.

Others to not share this opinion and shut off / open drain on glass so that it cannot take the hydro pressure.

Depends on club rules - some clubs want everything under steam tested (which makes sense to me).

jscarmozza wrote:When a completed engine that has been in service needs to be hydro tested, what is the procedure? Is the entire engine tested or are the relief valves, steam chests and cylinders, etc disconnected/removed and the holes plugged?

What did the inspector at your club have to say about hydro precedure?

What leakage rate (if any) is acceptable for a hydrostatic test of either boiler or individual piping? Sorry to jump in, but this has been on my mind


-jlakes85

Thanks Bill.
I'm still unaffiliated Builder.
John

jlakes85 wrote:What leakage rate (if any) is acceptable for a hydrostatic test of either boiler or individual piping? Sorry to jump in, but this has been on my mind


-jlakes85

Since you have not mentioned what your club inspector will accept, here's what is acceptable at the Finger Lakes Live Steamers. All of their boiler test forms are down loadable from the internet so you know exactly what to expect before getting the inspection.

In general, small weeps are acceptable on piping connections and glands. Zero is usually expected on the boiler. For a new boiler, it must be hydro tested to twice the working pressure. For a new boiler, this will be an "off the frames" inspection so it can be examined all over including the inside of the fire box. This test must have no leaks at welded joints, through plates, or through tubes, bushings or stays.

The yearly test requires only a hydro test at 150% of the working pressure and this is what the test forms from the FLLS are for.

The hydro is a cold test, there us also the "hot" test at the working pressure with fire in the hole to prove safety valves, safety valve dump capacity and pressure gauge.

Here's the link to the the test documents at the Finger Lakes Live Steamers:

http://fingerlakeslivesteamers.org/pdfi ... r_insp.pdf

You have not mentioned where you plan on running your locomotive.

David

No one has mentioned an important part of the hydrostatic test. It should be brought up slowly, and you should listen for any unusual noises. You actually can hear a stay break, or a seam opening up. This is more likely in older boilers than new construction.
Also, cold water is not a good idea. I believe the minimum temperature for a hydro test is 60 degrees F under ASME, 70 degrees F under FRA.

I heard a staybolt break on a full size locomotive once. Not during a hydro but fired up and not at full pressure. The telltale hole started weeping right away. It's not a sound that you forget!

Hi Marty,

If testing individual piping assemblies (throttle, aux/turret), are there any guidelines for leakage?

-jlakes85

I use "Master's with Metal" on everything from vacuum to high pressure steam - when nothing else works, Master's does. I went through everything on the market years ago and Master's is the only one that was 100% the first time.

DianneB wrote:I use "Master's with Metal" on everything from vacuum to high pressure steam - when nothing else works, Master's does. I went through everything on the market years ago and Master's is the only one that was 100% the first time.

I had to google that to see what it was.

Only found it at a Canadian supplier:

https://www.sinclairsupply.ca/index.jsp ... search&ID=

Steve

jlakes85 wrote:Hi Marty,

If testing individual piping assemblies (throttle, aux/turret), are there any guidelines for leakage?

-jlakes85

There are guide lines for what is acceptable in the PDF link I posted. Did you get a chance to check it out?

David